html,
body {
  font-family: 'PingFang SC',
    'Helvetica Neue',
    Helvetica,
    'Hiragino Sans GB',
    'Microsoft YaHei', '微软雅黑', Arial, sans-serif;
}

.content {
  width: 1200px;
  height: 100%;
  margin: 0 auto;
}